हिंदी

Verify Rolle'S Theorem for the Following Function on the Indicated Interval F(X) = X(X −2)2 on the Interval [0, 2] ?

Advertisements
Advertisements

प्रश्न

Verify Rolle's theorem for the following function on the indicated interval  f(x) = x(x −2)2 on the interval [0, 2] ?

योग
Advertisements

उत्तर

The given function is \[f\left( x \right) = x \left( x - 2 \right)^2\] , which can be rewritten as \[f\left( x \right) = x^3 - 4 x^2 + 4x\] .

We know that a polynomial function is everywhere derivable and hence continuous.
So, being a polynomial function, 

\[f\left( x \right)\]  is continuous and derivable on \[\left[ 0, 2 \right]\] .

Also,

\[f\left( 0 \right) = f\left( 2 \right) = 0\]

Thus, all the conditions of Rolle's theorem are satisfied.
Now, we have to show that there exists \[c \in \left[ 0, 2 \right]\] such that \[f'\left( c \right) = 0\] .

We have

\[f\left( x \right) = x^3 - 4 x^2 + 4x\]

\[ \Rightarrow f'\left( x \right) = 3 x^2 - 8x + 4\]

\[\text { When } f'\left( x \right) = 0 \]

\[ 3 x^2 - 8x + 4 = 0\]

\[ \Rightarrow 3 x^2 - 6x - 2x + 4 = 0\]

\[ \Rightarrow 3x\left( x - 2 \right) - 2\left( x - 2 \right) = 0\]

\[ \Rightarrow \left( x - 2 \right)\left( 3x - 2 \right)\]

\[ \Rightarrow x = 2, \frac{2}{3}\]

Thus, 

\[c = \frac{2}{3} \in \left( 0, 2 \right) \text{ such that } f'\left( c \right) = 0\]
Hence, Rolle's theorem is verified.
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 14: Mean Value Theorems - Exercise 15.1 [पृष्ठ ९]

APPEARS IN

आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
अध्याय 14 Mean Value Theorems
Exercise 15.1 | Q 2.7 | पृष्ठ ९

संबंधित प्रश्न

f (x) = [x] for −1 ≤ x ≤ 1, where [x] denotes the greatest integer not exceeding x Discuss the applicability of Rolle's theorem for the following function on the indicated intervals ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = x2 − 4x + 3 on [1, 3] ?


Verify Rolle's theorem for the following function on the indicated interval   f (x) = x(x − 4)2 on the interval [0, 4] ?


Verify Rolle's theorem for the following function on the indicated interval f (x) = x2 + 5x + 6 on the interval [−3, −2]  ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = sin x + cos x on [0, π/2] ?


Verify Rolle's theorem for the following function on the indicated interval f(x) = x2 − 5x + 4 on [1, 4] ?


It is given that the Rolle's theorem holds for the function f(x) = x3 + bx2 + cx, x  \[\in\] at the point x = \[\frac{4}{3}\] , Find the values of b and c ?


Examine if Rolle's theorem is applicable to any one of the following functions.
(i) f (x) = [x] for x ∈ [5, 9]
(ii) f (x) = [x] for x ∈ [−2, 2]
Can you say something about the converse of Rolle's Theorem from these functions?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem f(x) = x2 − 1 on [2, 3] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem  f(x) = x3 − 2x2 − x + 3 on [0, 1] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem  f(x) = x2 − 2x + 4 on [1, 5] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theore f(x) = (x − 1)(x − 2)(x − 3) on [0, 4] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theore  f(x) = tan−1 x on [0, 1] ?


Verify Lagrange's mean value theorem for the following function on the indicated intervals. find a point 'c' in the indicated interval as stated by the Lagrange's mean value theorem f(x) = x(x + 4)2 on [0, 4] ?


Find a point on the parabola y = (x − 4)2, where the tangent is parallel to the chord joining (4, 0) and (5, 1) ?


Find a point on the parabola y = (x − 3)2, where the tangent is parallel to the chord joining (3, 0) and (4, 1) ?


Find the points on the curve y = x3 − 3x, where the tangent to the curve is parallel to the chord joining (1, −2) and (2, 2) ?


Find a point on the curve y = x3 + 1 where the tangent is parallel to the chord joining (1, 2) and (3, 28) ?


State Lagrange's mean value theorem ?


If the polynomial equation \[a_0 x^n + a_{n - 1} x^{n - 1} + a_{n - 2} x^{n - 2} + . . . + a_2 x^2 + a_1 x + a_0 = 0\] n positive integer, has two different real roots α and β, then between α and β, the equation \[n \ a_n x^{n - 1} + \left( n - 1 \right) a_{n - 1} x^{n - 2} + . . . + a_1 = 0 \text { has }\].

 


Rolle's theorem is applicable in case of ϕ (x) = asin x, a > a in


When the tangent to the curve y = x log x is parallel to the chord joining the points (1, 0) and (e, e), the value of x is ______.


The value of c in Rolle's theorem for the function \[f\left( x \right) = \frac{x\left( x + 1 \right)}{e^x}\] defined on [−1, 0] is


The value of c in Rolle's theorem for the function f (x) = x3 − 3x in the interval [0,\[\sqrt{3}\]] is 

 


If f (x) = ex sin x in [0, π], then c in Rolle's theorem is



Find the maximum and minimum values of f(x) = secx + log cos2x, 0 < x < 2π


The maximum value of sinx + cosx is ______.


At x = `(5pi)/6`, f(x) = 2 sin3x + 3 cos3x is ______.


The least value of the function f(x) = 2 cos x + x in the closed interval `[0, π/2]` is:


If f(x) = ax2 + 6x + 5 attains its maximum value at x = 1, then the value of a is


Let y = `f(x)` be the equation of a curve. Then the equation of tangent at (xo, yo) is :- 


After finding critical points and identifying endpoints, what should be done next?


What is \[f(0)\] for \[f(x)=12x^{\frac{4}{3}}-6x^{\frac{1}{3}}\]?


What is \[f(1)\] for \[f(x)=12x^{\frac{4}{3}}-6x^{\frac{1}{3}}\]?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×